Fig 1.
Seasonal precipitation and average air temperature during study period, from April 2012 to March 2013.
(A) for site I, Guarapuava and (B) for site II, Taquarituba both located in Brazil. Blue bars referred to the precipitation, and red dashed lines represent the average seasonal temperature.
Table 1.
Description of sites and management practices adopted.
Fig 2.
The isotopic labeled-N (15N) fertilizer was applied only to the central microplot row installed in each plot.
Plants were sampled from the center part of the adjacent and the central rows.
Fig 3.
Data distribution for grain yield (A), plant N content (B) and NDFF (C) for the fertilizer N timing groups: fertilizer N applied to oats (N-OATS, red color), N applied at pre-plant and at planting time for corn (N-PLANT, green color), and in-season N added at V3 and at V3/V6 growth stages for corn (N-CORN, blue color).
Table 2.
Grain yield, plant N content, N derived from fertilizer (NDFF) and 15N recovery (NRE, %) by corn for all N fertilization treatments.
Fig 4.
Relationship between grain yield and plant N content (A), biomass and NDFF (B), and NDFF, plant N content (C), and the overall fertilizer fraction on plant N content for the fertilizer N timing groups: fertilizer N applied to oats (N-OATS, red color; n = 8), N applied at pre-plant and at planting time for corn (N-PLANT, green color; n = 16), and in-season N added at V3 and V3/V6 growth stages for corn (N-CORN, blue color; n = 16).
Table 3.
Distribution of N derived from fertilizer (NDFF) at corn harvest at varying soil depths from 0–20 cm, 20–40 cm, 40–60 cm, and overall 0–60 cm.
Fig 5.
Fate of N from fertilizer (A) and N source used by corn plants (B). Uppercase letters compare means of the components of the fate of N from fertilizer (A) or N source (B) within each fertilizer N timing level. Greek letters compare total N fertilizer recovered in the columns. Bars represent the standard error for each treatment.